The present invention relates to a method and a corresponding communication system for handling alarms using a management network which has a number of management levels, the alarm data for active alarms being transmitted for alarm realignment between an agent on one management level and at least one manager on a next highest management level.
The principles of a management network, which are also called TMN (Telecommunications Management Network) principles, define a number of management levels for managing a communication systemxe2x80x94for example a mobile communication systemxe2x80x94, each level having a dual function. In the managing system, every level except for the bottom one has a manager function for the level situated below it. In the managed system, every level except for the top one has an agent function for the next highest level.
Fault management is an important part of TMN management. In principle, the agent plays the active role here by recognizing, in good time and accurately, faults on its own management level and transmitting them as alarms to the manager on the next highest level. The transmission of alarm data from the agent to the manager is not critical as long as the communication mechanism between these systems is not impaired. If the connection between the two management levels, that is to say between the agent and the manager, is no longer ensured for a particular time, the agent must temporarily store the alarms which have occurred during this interval to ensure that, after the possibility of communication has been restored, an overview of the currently active alarmsxe2x80x94e.g. in the form of a listxe2x80x94is provided to the manager as quickly as possible, on the one hand, and, on the other hand, the manager can establish as complete an alarm history as possible both for the active and for the cleared alarms.
For this purpose, alarm realignment between the agent and the manager is carried out whenever a new connection is established after a connection has been terminated or after the agent or the manager has been initialized. All the alarm data for active alarms for which faults have not yet been cleared in the agentxe2x80x94which can be recognized from the fact that they are not identified as xe2x80x9ccleared alarmsxe2x80x9dxe2x80x94can therefore be provided to the next highest management level in full and as quickly as possible.
PCT Patent Application Ser. No. 96/24899 discloses a method with one or more managers and an agent, in which the intention is to reduce the number of notifications produced by the agent. Depending on defined parameter values, particular notifications generated in the agent are filtered out by discriminators, with the result that they no longer reach the manager as xe2x80x9cEvent reportsxe2x80x9d. Such discriminators do not reduce the processing load in the agent. The method therefore provides for the actual production of the notifications in the xe2x80x9cmanaged systemxe2x80x9d to be controlled by the operator on the xe2x80x9cmanaging systemxe2x80x9d, i.e. the agent should really only generate those notifications which are relevant to the manager and are therefore to be transmitted subsequently as xe2x80x9cEvent reportsxe2x80x9d via the manager/agent interface. The notifications in the agent are produced on the basis of a xe2x80x9cnotification stopxe2x80x9d attribute when the individual object instance is defined, with the result that transmission of the notifications is permitted or prevented depending on load.
The object of the invention is to provide a method and a communication system for handling alarms using a management network which has a number of management levels and optimizes alarm realignment between an agent and a number of mangers.
This object is achieved in accordance with the present invention in a method for handling alarms in a communication system using a management network having a number of management levels, wherein alarm data for active alarms is transmitted for parallel alarm realignments between an agent on a first management level and managers on a next highest management level, said method comprising the steps of:
transmitting from each of the managers to the agent at least one request having a request notification for transmission of alarm data; and
transmitting from the agent to a respective manager a number of notifications having the requested alarm data along with at least one item of correlation information for assigning a respective request to the notifications.
This object is also achieved in accordance with the present invention in a communication system for handling alarms using a management network which has a number of management levels, the alarm data for active alarms being transmitted for parallel alarm realignments between an agent on one management level and a number of managers on a next highest management level, the communication system comprising:
a number of managers each having:
a first transmitter for transmitting at least one request having a request notification for transmission of the alarm data, and
a first receiver for receiving a number of notifications having the requested alarm data along with items of correlation information for assigning the respective request to notifications; and
at least one agent having:
a second transmitter for transmitting to the manager the notifications having the requested alarm data along with the items of correlation information, and
a second receiver for receiving said transmissions from the manager.
The present invention is based on the alarm data for active alarms being transmitted for alarm realignment between an agent on one management level and at least one manager on a next highest management level. According to the present invention, the manager sends one or more request notifications to the agent for transmission of the alarm data, and correlation information for assigning the respective request to the notifications with the alarm data which are subsequently sent by the agent is received.
In the management network, the use of the correlation information according to the present invention means that a number of alarm realignments between the agent and one or more managers can take place simultaneously or serially. Parallel alarm handling results in better use of the transmission resources on the interface for the agent/manager relationship and allows the agent to provide the alarm data for active alarms more quickly for the next highest management level. The assignment on the basis of the correlation information provides the individual manager with the option, for both serial and parallel processes, of being able to assign the incoming responses from the agent with the alarm dataxe2x80x94in response to a number of requests from the managerxe2x80x94explicitly to the requestsxe2x80x94for example from various applications in the managerxe2x80x94even if the sequence is not observed. Requests sent in succession can overtake one another, for example if a packet network is being traversed between the agent and the manager. The agent can process a number of requests for realignment in parallel and, immediately thereafter, can send back the alarm data for realignment to the manager(s) without taking into account the sequence of the requests started and addressed to it.
A particular advantage of the present invention is that requests for the transmission of alarm data can be initiated by a number of managers in parallel and can be processed by the agent without affecting or interfering with one another. This is made possible, simply but effectively, by the correlation information. The notifications with the alarms on the communication path between the agent and the manager(s) can be allowed to overtake one another without corruptions or faults arising as a result. Furthermore, the present invention, characterized by the simultaneous transmission of the correlation information, allows the alarms transmitted on request for realignment to be distinguished from other alarms transmitted on the communication pathxe2x80x94the xe2x80x9cregularxe2x80x9d alarms.
In an embodiment the manager sends back, in the request notification, a (first) item of correlation information for assigning the respective request to the notifications with the alarm data which are subsequently sent by the agent, and the agent sends back to the manager a respective notification for starting the alarm realignment, said notification containing the first item of correlation information for the respective request and a further item of correlation information for assigning to the respectively started realignment the notifications with the alarm data which are subsequently sent by the agent. By initiating and transmitting the two items of correlation information in separate notifications, the manager can assign the requests to the notifications with the alarm data.
In an embodiment the agent also sends, in the respective notifications with the alarm data, the item of correlation information for assigning the notifications to the respectively started realignment. This ensures that the alarm data for different realignments taking place simultaneously reaches the manager, which processes each of the requested alarms further, irrespective of the instant at which it was transmitted by the agent.
In an embodiment, the agent, after sending the notifications with the alarm data, sends a respective notification for ending the alarm realignment to the manager, said notification containing the item of correlation information for the respective request. On the basis of the incoming item of correlation information, the managers can explicitly recognize the end of the notification sequence which contains alarm data and is intended for them in each case.
In an embodiment the agent uses one or more filter functions, which can each be controlled by an assignable manager, with filter criteria for the notifications produced by the agent, said notifications being routed to the manager only if the filter criteria are satisfied. The joint use of the filter mechanism provided generally for EVENT REPORTING in the management network has the advantage that the same filter criteria can be taken as a basis for realignment alarms as for the other alarms with virtually no additional complexity. Otherwise, the manager would, specifically, have to define these filter criteria first and specify them in the request which is to be evaluated by the agent in order to send the desired active alarms with the alarm data to the manager.
In an embodiment, a number of request notifications with correlation information which can in each case be assigned to the requests are sent by at least two managers. In this case, the managers for sending the request notifications, preferably for alarm realignment, are formed by different network elements in the management network. In accordance with one particularly preferred embodiment, the managers comprise various network management centers, in which case an item of correlation information for assigning the request to the respective network management center is sent together with the request notification.
In an embodiment, a number of request notifications with correlation information which can in each case be assigned to the requests are sent by one manager. In accordance with a preferred embodiment, the manager sends the request notifications to different applications in a physical network element in the management network. The manager can be an operation and maintenance center or a network management center, each with various applications, and can send a respective item of correlation information for assigning the request to the respective application together with the request notification.
According to the present invention, the communication system, in which the alarm data for active alarms is transmitted for alarm realignment between an agent on one management level and at least one manager on a next highest management level, comprises elements in the manager for sending one or more request notifications to the agent for transmission of the alarm data, and elements in the manager for receiving correlation information for assigning the respective request to the notifications with the alarm data which are subsequently sent by the agent.
These and other features of the invention(s) will become clearer with reference to the following detailed description of the presently preferred embodiments and accompanied drawings.